Deflected Shot Trajectory & xG Lab
Inspired by Matheus Cunha’s heavily deflected equalizer against Fulham. Explore how sudden deflection angles, ball velocity changes, and defender positioning wrong-foot goalkeepers and alter Expected Goals.
Simulation Pitch
Cunha Equalizer ScenarioThe Mathematics of Deflections
In high-level football, goalkeepers do not react purely on visual arrival; they commit early based on striker hip rotation and initial ball release trajectory. When an intervening defender clips the ball, two devastating physical shifts happen simultaneously:
- Vector Inversion: The deflection breaks the trajectory away from the goalkeeper's anticipated dive line, frequently sending the ball toward the opposite post.
- Deceleration & Parabolic Loop: Kinetic energy loss can cause the ball to lob gently over a grounded goalkeeper whose center of mass is already moving downward.
Frequently Asked Questions
How is Post-Deflection xG calculated here?
While standard pre-shot xG models measure shooter distance, angle, and defensive pressure, post-deflection expected goals evaluate the resulting shot vector, remaining distance to goal, and the goalkeeper's physical inability to reach the redirected ball before it crosses the goal line.
Why was Cunha's goal credited to him rather than an own goal?
Under IFAB and Premier League accreditation rules, if the attacker's initial shot is ruled to have been targeted on frame, the goal is awarded to the shooter even if a massive deflection completely redirected the path.
Can I test straight shots without deflection?
Yes, set the Deflection Angle slider to 0° to simulate a clean strike without defender interference.